Manhattan and Venice have always represented unsolved complexities for the modernist discourse in architecture. Anti-modern (Manhattan) and pre-modern (Venice), the two cities resist the separations and classifi cations that the modernist project imposes on architecture and urban space, remaining incomprehensible to it because they both are, in different ways, intrinsically indivisible. As it attempts to divide and to compartmentalize them and to superimpose its own categories, the modern project fails to comprehend their complexities, and can only partially address them, without fully understanding their structures, which remain for it ‘other’. Modernist planning that operates through divisions, zoning and separation of functions fi nds itself at odds with the organizational structures of these metropolises, failing to grasp the interplay of tensions and contradictions that they hold together – unresolved. Modernism fails to recognize that the orthogonal Grid of Manhattan and the paratactic canals-and-islands system of Venice are not planned fi gures but performative diagrams: operational spatial instructions for a performance rather than defi nitions and drawings of a form. Alternative categories are necessary to understand these two urban spaces, in their physical making as well as in their narratives and myths of self-representation.